Siderophore production by the magnetic bacterium Magnetospirillum magneticum AMB-1 is elicited by sufficient iron rather than by iron starvation. In order to clarify this unusual pattern, siderophore production was monitored in parallel to iron assimilation using the chrome azurol sulfonate assay and the ferrozine method respectively. Iron concentration lowered approximately ...

An orally available iron chelator is desirable for the treatment of secondary iron overload. Pyridoxal isonicotinoyl hydrazone (PIH) and its analogs effectively mobilize iron in vivo and in vitro, and are therefore promising candidates for this purpose. PIH analogs undergo significant amino acid-catalyzed hydrolysis in cell culture medium and in ...

New linear and tripodal tri-aza- and tetra-aza alkanoic acids or alkylbenzoic acids were prepared as basic structures for siderophore mimetics from polyamines and oxocarbonic acids or formylbenzoic acids by catalytic hydrogenation. From these acids acetylated tris- and tetrakiscatecholates or 8-acyloxy-2,4-dioxo-benzoxazine derivatives as well as compounds with spacer groups were synthesized. ...

Bacillus subtilis is able to synthesize a lipopeptide biosurfactant (known as surfactin), which is one of the most effective biosurfactants available. In our previous study, B. subtilis ATCC 21332 was used to produce surfactant and it was found that the addition of iron at an appropriate amount significantly improved the ...

The addition of exogenous pyrophosphate increases the growth yield and cAMP synthesis in stationary phase when Escherichia coli is grown in minimal medium. Pyrophosphate increases the yield by altering the enterobactin uptake system. We studied the physiological effects and examined how the E. coli transcriptome was modified when two structural ...

Humic acid (HA) has been shown to be a toxic factor for many mammalian cells, however the specific mechanism of the cytotoxicity induced by HA remains unclear. From the assessment of its redox properties, HA has been shown to be capable of reducing iron(III) to iron(II) in aqueous conditions over ...

In 1999, we first reported that a white rot fungus, Ceriporiopsis subvermispora produced a series of novel alkylitaconic acids (ceriporic acids). In the present paper we synthesized the metabolite, 1-nonadecene-2,3-dicarboxylic acid (ceriporic acid B) by Grignard reaction to analyze chemical properties of the alkylitaconates. Mass spectrometer (MS) and nuclear magnetic ...

Naturally occurring variation detected in the germplasm of maize and wheat, two of the top three cereal crops in the world, provides options for incorporating higher levels of iron, zinc, and beta-carotene into these grains. In addition, quality protein maize (QPM) has been developed from naturally occurring variation; its seed ...

Serum levels of uric acid (UA), an inhibitor of peroxynitrite- (ONOO-) related chemical reactions, became elevated approximately 30 million years ago in hominid evolution. During a similar time frame, higher mammals lost the ability to synthesize another important radical scavenger, ascorbic acid (AA), leading to the suggestion that UA may ...

Adequate bioavailable Fe intake is essential for optimal growth and intellectual development of infants and children. Fruit juices are nutritious and popular drinks for infants and children and are known to contain Fe uptake inhibitors (e.g., polyphenolic compounds) and a dominant promoter, ascorbic acid. Ascorbic acid is naturally present in ...

Arsenic adsorption was carried out on simple materials such as goethite and amorphous iron hydroxide, and more complex matrices such as clay pillared with titanium(IV), iron(III), and aluminum(III). These matrices were synthesized from a bentonite whose montmorillonitic fraction was pillared according to optimized parameters. These sorbents were characterized by various ...

During reductive dechlorination of trichloroethene (TCE) by zero-valent iron, stable carbon isotopic values of residual TCE fractionate significantly and can be described by a Rayleigh model. This study investigated the effect of observed reaction rate, surface oxidation and iron type on isotopic fractionation of TCE during reductive dechlorination. Variation of ...

The anti- and prooxidative properties of gallic acid in Fenton-type systems containing H(2)O(2) and Fe(III) were examined in pH 3-10 reaction media and at reaction temperatures of 20-50 degrees C. Although it is a free radical scavenger, gallic acid may exhibit prooxidative properties, as it promotes the production of hydroxyl ...

Ethylenediamine-N,N'bis(o-hydroxyphenyl)acetic acid (o,o-EDDHA) is one of the most efficient iron chelates employed to relieve iron chlorosis in plants. However, the presence of positional isomers of EDDHA in commercial iron chelates has been recently demonstrated, and among them, it has been claimed that ethylenediamine-N(o-hydroxyphenylacetic)-N'(p-hydroxyphenylacetic) acid (o,p-EDDHA) is the main impurity present ...

Sustainable management of acidic mining lakes requires knowledge on the origin and reactivity of its sedimentary organic matter. We identified different pools of organic matter (OM) in the Fe-rich sediment (up to 35 wt %) of an acidic (pH 2.8) mining lake using delta13C-signals, C/N ratios, and the markers alkanes, ...

It has previously been suggested that organic acids enhance iron absorption. We have studied the effect of nine organic acids on the absorption of Fe(II) and Fe(III) in the human epithelial cell line Caco-2. The effect obtained was dose-dependent, and the greatest increase (43-fold) was observed for tartaric acid (4 ...

We have converted cytochrome P450 BM-3 from Bacillus megaterium (P450 BM-3), a medium-chain (C12-C18) fatty acid monooxygenase, into a highly efficient catalyst for the conversion of alkanes to alcohols. The evolved P450 BM-3 exhibits higher turnover rates than any reported biocatalyst for the selective oxidation of hydrocarbons of small to ...

A cellulolytic active oxygen species, hydroxyl radicals (.OH), play a leading role in the erosion of wood cell walls by brown-rot and non-selective white-rot fungi. In contrast, selective white-rot fungi have been considered to possess unknown systems for the suppression of .OH production due to their wood decay pattern with ...

Low-fat (5.9-10.3% fat) cooked sausages were produced with seven different formulations. Sausages produced with total replacement of fat with sunflower oil had significantly lower oleic acid (C18:1) and higher linoleic (C18:2) and behenic (C22:0) fatty acid contents. Their ratio of TUFA/TS was 3.65 compared to 0.95-1.14 for the other sausages. ...

Iron deficiency, one of the main worldwide nutritional deficiencies, results from the low bioavailability of most dietary iron, including cow milk. Hydrolysis of the cow milk protein casein produces low molecular weight caseinophosphopeptides (CPPs). Binding of iron to CPPs keeps it soluble in the digestive tract and prevents the formation ...

This study aimed to quantify concentrations of fatty acids in the hump and abdomen fats of three different age groups of camel. Hump and abdomen fats were extracted from eight each of one-humped camels (Camelus dromedarius) of three age groups: group 1 (<1 year old), group 2 (1-3 years old) ...

BACKGROUND: Short-chain fatty acids produced by bacterial fermentation in the colon enhance the local absorption of cations, such as calcium, that could be used to improve the bioavailability of iron if a significant colonic absorption of iron were to occur. METHODS: Iron (iron gluconate, 100 microM) absorption by the caecum ...

Pyridoxal isonicotinoyl hydrazone (PIH) analogues are effective iron chelators in vivo and in vitro, and may be of value for the treatment of secondary iron overload. The sensitivity of Jurkat cells to Fe-chelator complexes was enhanced several-fold by the depletion of the antioxidant glutathione, indicating the role of oxidative stress ...

We all depend on molecular oxygen and heme for our life, as evident from the pigments in blood and daily wastes. About 80% of serum bilirubin is derived from hemoglobin of senescent erythrocytes, which have finished their mission of 120 days and have been phagocytized by macrophages in the reticuloendothelial ...

In Yangmingshan National Park, located in the northern part of the Taiwan Island, there is a very rare area where fish (Channa asiatica) live in spite of acid environments. The origin of the acid in local acid ponds and rivers and the evolution of the water chemistry are discussed on ...

Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. With ascorbic acid the rate of iron release from HLF by DMA(V) was intermediate (3.37 nM/min, P<0.05) and by DMA(III) was much higher (16.3 nM/min, P<0.001). No ...

New acylated bis-catecholates and 1,3-benzoxazine-2,4-dione derivatives based on secondary diamino acids (N-(aminoalkyl)glycines, N-aminopropyl-alanine, and N-aminopropyl-4-aminovaleric acid), on N-(aminoalkyl)aminomethyl benzoic acids, on N-(aminoalkyl)aminomethyl phenoxyacetic acids, or on 3,5-diaminobenzoic acid were synthesized as artificial siderophores. The corresponding diamino acids were obtained from the diamines and oxocarboxylic acids by catalytic hydrogenation. The acylated ...

OBJECTIVE: To compare the differences in glycyrrhizic acid contents of Gegenqinlian decoctions (a traditional Chinese herbal preparation) prepared according to varied prescription, so as to establish a referential standard for controlling the acid level in such preparations. METHODS: Reverse phase-high performance liquid chromatography (RP-HPLC) was employed to determine the content ...

The effect of ethanol, zinc, and iron (Fe(2+) and Fe(3+)) concentration and of oxygen supply on cell growth and the production of citric acid (CA) and isocitric acid (ICA) from ethanol by mutant Yarrowia lipolytica N 1 was studied under continuous cultivation. The following peculiarities of Y. lipolytica metabolism were ...

To test the effect of protein conformation on reactivity, we use laser flash photolysis to compare the electron-transfer properties of the triplet state of zinc-substituted cytochrome c, designated (3)Zncyt, in the folded forms at low (F(low)) and high (F(high)) ionic strength, molten-globule (MG) form, and the forms unfolded by acid ...

We showed recently that iron + ascorbate can impair the assembly of intestinal lipoproteins. However, we could not determine whether these changes were caused by iron + ascorbate-mediated lipid peroxidation per se. We therefore conducted studies to evaluate how antioxidants antagonize the iron + ascorbate-induced derangements. To this end, Caco-2 ...

OBJECTIVE: Iron deficiency is estimated to affect about 30% of the world population. Iron supplementation in the form of tablets and food fortification has not been successful in developing countries, and iron deficiency is still the most important deficiency related to malnutrition. Here we present experiments that aim to increase ...

Fluorescence quenching is commonly used to study the extent of metal binding to humic acid or fulvic acid. By studying this phenomenon, the hydrolysis and precipitation behaviors of polymeric and monomeric iron coagulants in the coagulation of humic acid were evaluated. Combined measurements of fluorescence intensity and dissolved organic carbon ...

Ferritin is the main intracellular iron storage protein. The release of iron from ferritin in the presence of a number of phenolic based compounds of nutritional significance was studied at physiological pH. The release of iron was measured by monitoring the formation of the iron(II)-ferrozine complex. The kinetics of this ...

Several iron chelators containing alpha,beta-unsaturated hydroxamic acid motifs appended to a citric acid platform were synthesized. Mycobacterium paratuberculosis was then challenged to grow in the presence of a panel of siderophores (mycobactin J, deferrioxamine B, acinetoferrin, and nannochelin A) and the new synthetic agents. Of the structures tested, those containing ...

Finger millet (Eleusine coracana), kidney beans (Phaseolus vulgaris), peanuts (Arachis hypogoea), and mango (Mangifera indica) were processed separately and then combined, on the basis of their amino acid scores and energy content, into a complementary food for children of weaning age. The finger millet and kidney beans were processed by ...

The study was designed to compare the fatty acid profiles and triglyceride composition of subcutaneous and intramuscular fat of raw and cured hams from Hairless Mexican Pigs. Curing (180 days) was developed throughout several ordered steps: salting, stabilization, drying and ripening. For the salting step, hams were rubbed with nitrate ...

The mechanisms of photodegradation of binary iron- and uranium-citrate and ternary iron-uranium-citrate complexes were elucidated. Citric acid degradation products were identified by HPLC and GC, and the metal precipitates were identified by XRD and EXAFS. Photodegradation of a binuclear iron-citrate complex occurred as a result of two one-electron oxidations of ...

Konrad Bloch developed an interest in insects because they are unable to make sterols, and in yeast because these cells need oxygen to make sterols and unsaturated fatty acids. Insects, like all other organisms, must deal with the toxic effects of oxygen in the presence of iron, which itself is ...

The present work is a study of a series of Ti-7.5Mo-xFe alloys, with the focus on the effect of iron addition on the structure and mechanical properties of the alloys. Experimental results indicate that alpha" phase-dominated binary Ti-7.5Mo alloy exhibited a fine, acicular martensitic structure. When 1 wt% or more ...

A 52-year-old man presented to his primary care physician with blisters and sores on the backs of his hands. Laboratory studies supported a diagnosis of porphyria cutanea tarda, complicated by the presence of both the C282Y and H63D mutations in the HFE gene, with susequent iron over-load. This case illustrates ...

Cytochrome P450 isolated from Bacillus subtilis (P450BSbeta; MW 48 kDa) catalyzes the hydroxylation of long-chain fatty acids at the alpha and beta positions using H(2)O(2) as an oxidant. Crystals of the substrate-free form of P450BSbeta belonging to the trigonal space group P3(2)21 or P3(1)21 were obtained by the sitting-drop vapour-diffusion ...

A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions. The dominant features ...

Twenty male Comisana lambs were equally divided into two groups. Ten subjects were artificially reared, 10 others were ewe reared and used as control. Unseparated control animals displayed increased cellular immune response to a percutaneous injection of phytohemagglutinin (P<0.001). During the open field test, ewe-reared lambs showed a higher number ...

Iron incorporation by bovine spleen apoferritin either with ferrous ammonium sulfate in different buffers or with ferrous ammonium sulfate and phosphate was studied. Iron uptake and iron autoxidation were recorded spectrophotomerically. The buffers [4-(2-hydroxyethyl)-1-piperazinyl]ethanesulphonic acid (Hepes) and tris(hydroxymethyl)aminoethane (Tris) exhibited pH-dependent iron autoxidation, with Tris showing less iron autoxidation than ...

Populations that depend on grains and legumes as staple foods consume diets rich in phytic acid (myo-inositol-1,2,3,4,5,6-hexkisphosphate), the storage form of phosphorus in seeds. This compound binds tightly to important mineral nutrients such as iron and zinc, forming salts that are largely excreted. This phenomenon can contribute to mineral depletion ...

The seventeenth-century Swedish warship, Vasa, was recovered in good condition after 333 years in the cold brackish water of Stockholm harbour. After extensive treatment to stabilize and dry the ship's timbers, the ship has been on display in the Vasa Museum since 1990. However, high acidity and a rapid spread ...

BACKGROUND: Transferrin is the major iron binding protein in human plasma. In black persons, the transferrin CD phenotype has been associated with alterations in certain markers of iron status. OBJECTIVE: We studied vitamin C status in a Zimbabwean population according to transferrin phenotype because vitamin C metabolism is influenced by ...

The objective of this study was to document the effects of phytic acid, tannic acid, and zinc on iron uptake in an in vitro digestion/Caco-2 cell culture model. The effects of phytic acid and tannic acid on iron uptake were measured at increasing molar ratios of FeCl3 to phytic acid ...